3D Printing with Carbon Concrete (2020-11)¶

3D printing with cementitious materials requires suitable solutions for the integration of reinforcement during the manufacturing process. This paper presents a new technology that uses mineral-impregnated carbon-fiber (MCF) yarns for this purpose. This new type of non-corrosive reinforcement has excellent mechanical properties, high sustainability and durability. Crucially, however, MCF offers extremely high technological flexibility, as it can be easily shaped and processed fully automatically when fresh. The article describes a new nozzle developed for the integration of MCF reinforcement directly into concrete filaments in extrusion-based 3D printing processes. Three carbon yarns were simultaneously introduced into each concrete layer. The existing test methods were adapted to assess the tensile and flexural behavior of printed carbon concrete as well as the quality of the bond between reinforcement and concrete. The tests revealed a mechanical performance of the printed concrete that is comparable to that of textile concrete made from carbon fibers. The research presented has demonstrated the feasibility and the very high potential of the new technology in terms of the digitalization and automation of concrete construction.